When obtaining each pixel of a raw image, a light-sensitive chip of a camera can obtain only a value of one color component of three color components red, green, and blue (R/G/B) of each pixel. In order to obtain a bitmap (BMP) image, values of the other two color components of the pixel need to be obtained by estimation by using a correlation between three color components of a current pixel and surrounding pixels in the RAW image. A similar operation may be performed on each pixel in the RAW image to obtain a complete color BMP image. This process is referred to as interpolation or demosaicing.
A simplest algorithm used in the foregoing process is a bi-linear interpolation algorithm, where processing is performed on R, G, and B separately without considering a correlation between the three. A complex interpolation algorithm takes advantage of a correlation between the three, R, G, and B, and takes different directions into consideration. In a long-term process of research and development, the inventor of the present application finds that fluctuation, in an adjacent domain, of a color component in which a current pixel is located is transferred to other two color components obtained by interpolation, thereby resulting in crosstalk of an incorrect color.